Corrosion<\/a> is the alteration of a material (usually metallic) due to an electrochemical reaction with its surrounding environment. The speed and form in which corrosion occurs depend on the chemical composition of the water but are also influenced by other factors such as the properties of the metallic material, the design and construction of the hydraulic system, its management, and, importantly, the disinfection process.
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\n\u00a0<\/p>\n\nCorrosive processes chemically erode and thin the metal material over time. Common consequences include discolouration, odour, and abnormal taste in the water, caused by the release of compounds from the corrosion process, and the development of cracks in the pipes leading to leaks.<\/p>\n\n
Plastics are also susceptible to degradation, which can alter their structure, causing embrittlement and a loss of mechanical properties. In most cases, these effects are caused by the breaking of the bonds holding together the polymer chains in the plastics. This can result in the glassification or powdering of the plastic, which becomes thinner and more prone to breakage.<\/p>\n\n
As mentioned earlier, disinfection can significantly affect these processes, especially since many disinfectants used for water treatment are oxidising agents and highly reactive.<\/p>\n\n
Corrosion and chlorine-based disinfectants<\/h2>\n\n
Although widely used for water disinfection, sodium hypochlorite and chlorine dioxide are well known for their detrimental effects on the materials that make up water distribution systems and facilities. With oxidation-reduction potentials of 800-900 mV and 900-950 mV, respectively, they are considered strong oxidants.<\/p>\n\n
Their high reactivity triggers chemical reactions with the materials in the pipes, causing the aforementioned effects. In the case of hypochlorite, its harmful impact is particularly noticeable on metals. Scientific studies have demonstrated the effect of corrosive processes on disinfectant consumption, leading to increased dosing requirements to maintain microbiological control and, in turn, worsening corrosion.<\/p>\n\n
Chlorine dioxide is also highly aggressive and incompatible with both metals and plastics. Due to its nature as a dissolved gas, chlorine dioxide can penetrate the three-dimensional polymer matrix of plastic materials (such as polyethylene and polypropylene), breaking the bonds between polymer chains and causing the damage previously described.<\/p>\n\n
Monochloramine: Disinfection without corrosion<\/h2>\n\n
Although it belongs to the chlorine-based disinfectant family, monochloramine has distinct characteristics and properties compared to other compounds in the same group. The Cl-N bond makes chlorine more stable, and as a result, monochloramine is less oxidising and reactive. Its oxidation-reduction potential is approximately half that of sodium hypochlorite and chlorine dioxide.<\/p>\n\n
This significantly lower chemical reactivity translates into greater compatibility with materials: monochloramine does not trigger oxidative reactions in either metals or plastics. Numerous scientific publications document the complete absence of corrosion or premature ageing in system components exposed to monochloramine, even with prolonged use (over several years). These findings are particularly important because they refer to the use of monochloramine in hot water systems, where it is well known that corrosive processes are accelerated by higher temperatures.<\/p>\n\n
Regarding compatibility, the only issue to note is the possible alteration of certain low-quality rubber types (such as those used in seals or o-rings). However, these are typically poorly performing and not suited for high-quality applications.<\/p>\n","protected":false},"excerpt":{"rendered":"
Monochloramine: disinfectant effectiveness for the microbiological safety of water without unwanted effects on pipeline materials.<\/p>\n","protected":false},"author":2,"featured_media":2399,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[33],"tags":[],"class_list":["post-2709","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-science"],"_links":{"self":[{"href":"https:\/\/www.monoclorammina.it\/en\/wp-json\/wp\/v2\/posts\/2709","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.monoclorammina.it\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.monoclorammina.it\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.monoclorammina.it\/en\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.monoclorammina.it\/en\/wp-json\/wp\/v2\/comments?post=2709"}],"version-history":[{"count":1,"href":"https:\/\/www.monoclorammina.it\/en\/wp-json\/wp\/v2\/posts\/2709\/revisions"}],"predecessor-version":[{"id":2710,"href":"https:\/\/www.monoclorammina.it\/en\/wp-json\/wp\/v2\/posts\/2709\/revisions\/2710"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.monoclorammina.it\/en\/wp-json\/wp\/v2\/media\/2399"}],"wp:attachment":[{"href":"https:\/\/www.monoclorammina.it\/en\/wp-json\/wp\/v2\/media?parent=2709"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.monoclorammina.it\/en\/wp-json\/wp\/v2\/categories?post=2709"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.monoclorammina.it\/en\/wp-json\/wp\/v2\/tags?post=2709"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}